#include<bits/stdc++.h>
using namespace std;
int main()
{
	int y,m,d=1;
	scanf("%d,%d",&y,&m);
	if(y%4==0&&y%100!=0||y%400==0)
	{
		switch(m)
		{
			case 1: 
			case 3: 
			case 5: 
			case 7: 
			case 8:
			case 10: 
			case 12:d=31;break;
			case 4: 
			case 6:
			case 9: 
			case 11:d=30;break;
			case 2:d=29;break;
			default:d=0;		
		}
	}
	else
	{
		switch(m)
		{
			case 1: 
			case 3: 
			case 5: 
			case 7: 
			case 8:
			case 10: 
			case 12:d=31;break;
			case 4: 
			case 6:
			case 9: 
			case 11:d=30;break;
			case 2:d=28;break;
			default:d=0;		
		}	
	}
	d!=0?cout<<d:cout<<"Error";
    return 0;
}

